In a recent post to the 9Lessons.info site, Srinivas Tamada shows you how to connect Gmail with your system to import contacts via the magic of OAuth (pulled from Gmail to you).

Inviting friends is the most important part of the web project success. This post explains you how to import Gmail contacts from address book via Google open authorization protocol connect with PHP. It’s simple just few configurations follow below four steps, use this script and give option to invite more friends.

Following a few simple steps and using this simple script - registering the domain under Google Accounts, verify ownership and use the OAuth consumer and secret keys in the script. It's then simple to grab the contacts and output their details as the "Contacts.php" example script shows.